<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		<div id="wrap">
			<div></div>
			<div></div>
			<div id="box">box</div>
			<div></div>
		</div>
		<script type="text/javascript">
			var oDiv = document.getElementById("wrap")
			var aDiv = oDiv.getElementsByTagName("div")
			console.log(aDiv)
			//CSS选择器怎么查找，就在querySelectorAll中写
			var aDiv2 = document.querySelectorAll("#wrap div")
			console.log(aDiv2)
			//不要忘记写#
			var oBox = document.querySelector("#box")
			console.log(oBox)
		</script>
	</body>
</html>
